Organic acid modified biochar as well as preparation method and application thereof

Abstract

The invention relates to the technical field of biochar preparation, and discloses organic acid modified biochar as well as a preparation method and application thereof. The preparation method of the organic acid modified biochar comprises the following steps: 1) performing calcination modification on biochar to obtain primary modified biochar; (2) putting the primary modified biochar prepared in the step (1) into hydrochloric acid, and carrying out impregnation modification on the primary modified biochar to obtain secondary modified biochar; and 3) mixing lauric acid, octadecylamine and the secondary modified biochar prepared in the step 2), heating, dipping and modifying to obtain the organic acid modified biochar. The anti-permeability coefficient of the organic acid modified biochar provided by the invention can reach 0.54 * 10 <-8 > m / s, and the organic acid modified biochar has excellent anti-permeability performance and can be applied to anti-permeability of building engineering.

Description

Technical Field

[0001] The present invention relates to the technical field of biochar preparation, and in particular to an organic acid modified biochar and a preparation method and application thereof. Background Art

[0002] The anti-seepage and water-stopping of buildings has always been the focus of people's attention. It has an extremely significant impact on the safety and durability of buildings: from the perspective of durability, long-term leakage will cause corrosion to the building structure, thereby reducing the strength of the structure. This corrosion will weaken the earthquake resistance and pressure resistance of the house, and thus cause great damage to the durability of the building; from the perspective of safety, if the building structure suffers from leakage for a long time, its internal moisture content will increase significantly, which will aggravate the degree of corrosion of the steel bars and circuit pipelines inside the wall. This corrosion will not only lead to a decrease in the bearing capacity of the wall, but may also cause problems such as short circuits or poor contact of wires in the wall, thereby bringing serious safety risks and reducing the overall safety of the building.

[0003] Therefore, how to improve the anti-seepage performance of buildings has become a technical problem that needs to be solved urgently by those skilled in the art. Summary of the invention

[0004] The purpose of the present invention is to provide an organic acid modified biochar and a preparation method and application thereof, wherein the organic acid modified biochar has excellent anti-seepage performance.

[0005] To achieve the above object, the present invention provides the following technical solutions:

[0006] One of the technical solutions of the present invention:

[0007] A method for preparing organic acid-modified biochar comprises the following steps:

[0008] 1) calcining and modifying the biochar to obtain primary modified biochar;

[0009] 2) placing the primary modified biochar prepared in step 1) in hydrochloric acid to perform impregnation modification on the primary modified biochar to obtain secondary modified biochar;

[0010] 3) mixing lauric acid, octadecylamine and the secondary modified biochar prepared in step 2), heating, and impregnating and modifying the biochar to obtain the organic acid modified biochar.

[0011] Furthermore, in step 1), the calcination modification is specifically: under the protection of nitrogen gas, the biochar is preheated at 200-300° C. for 20 minutes, and then calcined and modified at 700-750° C. for 10 minutes.

[0012] Furthermore, in step 2), the concentration of the hydrochloric acid is 0.05 to 0.20 mol·L-1 .

[0013] Furthermore, in step 2), the volume ratio of the primary modified biochar to hydrochloric acid is 1 g: 20 mL.

[0014] Furthermore, in step 2), the impregnation modification is specifically: impregnation modification at 70-90° C. for 30 minutes.

[0015] Furthermore, in step 3), the mass ratio of lauric acid, octadecylamine and secondary modified biochar is (5-10):(3-5):1.

[0016] Furthermore, in step 3), the heating is specifically: heating to 55° C. to completely melt the lauric acid and octadecylamine.

[0017] Furthermore, in step 3), the impregnation modification is specifically: impregnation modification at 55° C. for 2 to 3 hours.

[0018] Furthermore, in step 3), before the impregnation modification, the pH of the reaction system needs to be adjusted to 5.

[0019] The second technical solution of the present invention:

[0020] The organic acid-modified biochar prepared by the above-mentioned method for preparing organic acid-modified biochar.

[0021] The third technical solution of the present invention:

[0022] The application of the organic acid-modified biochar prepared by the above-mentioned method for preparing organic acid-modified biochar in anti-seepage of building engineering.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] The organic acid modified biochar provided by the present invention has an anti-seepage coefficient of up to 0.54×10 -8 m / s, has excellent anti-seepage performance and can be used in anti-seepage of building engineering. DETAILED DESCRIPTION

[0025] Now, various exemplary embodiments of the present invention are described in detail, and this detailed description should not be considered as a limitation of the present invention, but should be understood as a more detailed description of certain aspects, characteristics and embodiments of the present invention. It should be understood that the terms described in the present invention are only for describing specific embodiments and are not used to limit the present invention.

[0026] In addition, for the numerical range in the present invention, it is understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Each smaller range between the intermediate value in any stated value or stated range and any other stated value or intermediate value in the range is also included in the present invention. The upper and lower limits of these smaller ranges can be independently included or excluded in the scope.

[0027] Unless otherwise indicated, all technical and scientific terms used herein have the same meanings as those generally understood by those skilled in the art. Although the present invention describes only preferred methods and materials, any methods and materials similar or equivalent to those described herein may also be used in the implementation or testing of the present invention. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials associated with the documents. In the event of a conflict with any incorporated document, the content of this specification shall prevail.

[0028] It will be apparent to those skilled in the art that various modifications and variations may be made to the specific embodiments of the present invention description without departing from the scope or spirit of the present invention. Other embodiments derived from the present invention description will be apparent to the skilled artisan. The present invention description and examples are exemplary only.

[0029] The words “include,” “including,” “have,” “contain,” etc. used in this document are open-ended terms, meaning including but not limited to.

[0030] In the following examples, all the raw materials used were commercially available, wherein the biochar was MF8 powdered activated carbon purchased from Shandong Yuyang Activated Carbon Co., Ltd.

[0031] In the following examples, a method for preparing organic acid-modified biochar comprises the following steps:

[0032] 1) Under nitrogen protection, the biochar is preheated at 200-300° C. for 20 min, and then calcined at 700-750° C. for 10 min to obtain a primary modified biochar;

[0033] 2) According to the volume ratio of primary modified biochar to hydrochloric acid of 1 g: 20 mL, the primary modified biochar prepared in step 1) is placed in a solution with a concentration of 0.05 to 0.20 mol·L -1 The biochar was modified by immersing in hydrochloric acid at 70-90°C for 30 minutes, washing, and drying to obtain secondary modified biochar;

[0034] 3) According to the mass ratio of lauric acid, octadecylamine and secondary modified biochar of (5-10):(3-5):1, lauric acid, octadecylamine and the secondary modified biochar prepared in step 2) are mixed, heated to 55°C, and after lauric acid and octadecylamine are completely melted, the pH of the reaction system is adjusted to 5, and the biochar is immersed and modified at 55°C for 2-3 hours, filtered while hot, washed, and dried to obtain the organic acid modified biochar.

[0035] Examples 1 to 6

[0036] Organic acid modified biochar

[0037] 1) Under nitrogen protection, the biochar was preheated at 250°C for 20 min, and then calcined and modified at 700°C, 710°C, 720°C, 730°C, 740°C or 750°C for 10 min to obtain a primary modified biochar;

[0038] 2) According to the volume ratio of primary modified biochar to hydrochloric acid of 1 g: 20 mL, the primary modified biochar prepared in step 1) was placed in a solution with a concentration of 0.05 mol·L -1 The biochar was immersed in hydrochloric acid at 70°C for 30 min, washed and dried to obtain secondary modified biochar;

[0039] 3) According to the mass ratio of lauric acid, octadecylamine and secondary modified biochar of 5:3:1, lauric acid, octadecylamine and the secondary modified biochar prepared in step 2) are mixed, heated to 55°C, and after lauric acid and octadecylamine are completely melted, the pH of the reaction system is adjusted to 5, and the biochar is immersed and modified at 55°C for 2h, filtered while hot, washed, and dried to obtain the organic acid modified biochar.

[0040] The anti-seepage performance of the organic acid-modified biochar prepared in Examples 1 to 6 was tested, and the results of the anti-seepage performance test are shown in Table 1;

[0041] Table 1 Anti-seepage performance test results

[0042]

[0043] It can be seen from the data in Table 1 that changing the calcination temperature during the first modification will affect the anti-permeability properties of the organic acid modified biochar to a certain extent. Within the calcination temperature range of 700-750°C, with the increase of the calcination temperature, the anti-permeability properties of the organic acid modified biochar first gradually increase, and then gradually decrease. The optimal anti-permeability properties are reached at 720°C, so 720°C is the optimal calcination temperature.

[0044] Embodiments 7 to 9

[0045] Organic acid modified biochar

[0046] 1) Under nitrogen protection, the biochar was preheated at 250°C for 20 min, and then calcined at 720°C for 10 min to obtain a primary modified biochar;

[0047] 2) According to the volume ratio of primary modified biochar to hydrochloric acid of 1 g: 20 mL, the primary modified biochar prepared in step 1) was placed in a solution with a concentration of 0.10 mol·L -1 、0.15mol·L -1 or 0.2mol·L -1 The biochar was immersed in hydrochloric acid at 70°C for 30 min, washed and dried to obtain secondary modified biochar;

[0048] 3) According to the mass ratio of lauric acid, octadecylamine and secondary modified biochar of 5:3:1, lauric acid, octadecylamine and the secondary modified biochar prepared in step 2) are mixed, heated to 55°C, and after lauric acid and octadecylamine are completely melted, the pH of the reaction system is adjusted to 5, and the biochar is immersed and modified at 55°C for 2h, filtered while hot, washed, and dried to obtain the organic acid modified biochar.

[0049] The anti-seepage performance of the organic acid-modified biochar prepared in Examples 7 to 9 was tested, and the results of the anti-seepage performance test are shown in Table 2;

[0050] Table 2 Anti-seepage performance test results

[0051]

[0052] From the data in Table 2, it can be seen that changing the hydrochloric acid concentration during secondary modification will affect the anti-seepage performance of organic acid modified biochar to a certain extent. -1 Within the concentration range of 0.10 mol·L -1 The best anti-seepage performance was achieved when 0.10 mol·L -1 is the optimal hydrochloric acid concentration.

[0053] Embodiments 10 to 13

[0054] Organic acid modified biochar

[0055] 1) Under nitrogen protection, the biochar was preheated at 250°C for 20 min, and then calcined at 720°C for 10 min to obtain a primary modified biochar;

[0056] 2) According to the volume ratio of primary modified biochar to hydrochloric acid of 1 g: 20 mL, the primary modified biochar prepared in step 1) was placed in a solution with a concentration of 0.10 mol·L -1The biochar was modified by immersing in hydrochloric acid at 75°C, 80°C, 85°C or 90°C for 30 min, washing and drying to obtain secondary modified biochar;

[0057] 3) According to the mass ratio of lauric acid, octadecylamine and secondary modified biochar of 5:3:1, lauric acid, octadecylamine and the secondary modified biochar prepared in step 2) are mixed, heated to 55°C, and after lauric acid and octadecylamine are completely melted, the pH of the reaction system is adjusted to 5, and the biochar is immersed and modified at 55°C for 2h, filtered while hot, washed, and dried to obtain the organic acid modified biochar.

[0058] The anti-seepage performance of the organic acid-modified biochar prepared in Examples 10 to 13 was tested, and the results of the anti-seepage performance test are shown in Table 3;

[0059] Table 3 Anti-seepage performance test results

[0060]

[0061] It can be seen from the data in Table 3 that changing the impregnation modification temperature during secondary modification will affect the anti-permeability properties of organic acid modified biochar to a certain extent. Within the impregnation modification temperature range of 70-90°C, with the increase of the impregnation modification temperature, the anti-permeability properties of organic acid modified biochar first gradually increase, and then gradually decrease. The optimal anti-permeability properties are reached at 80°C, so 80°C is the optimal impregnation modification temperature.

[0062] Embodiments 14 to 18

[0063] Organic acid modified biochar

[0064] 1) Under nitrogen protection, the biochar was preheated at 250°C for 20 min, and then calcined at 720°C for 10 min to obtain a primary modified biochar;

[0065] 2) According to the volume ratio of primary modified biochar to hydrochloric acid of 1 g: 20 mL, the primary modified biochar prepared in step 1) was placed in a solution with a concentration of 0.10 mol·L -1 The biochar was immersed in hydrochloric acid at 80°C for 30 min, washed and dried to obtain secondary modified biochar;

[0066] 3) According to the mass ratio of lauric acid, octadecylamine and secondary modified biochar recorded in Table 4, lauric acid, octadecylamine and the secondary modified biochar prepared in step 2) are mixed, heated to 55°C, and the lauric acid and octadecylamine are completely melted, the pH of the reaction system is adjusted to 5, and the mixture is immersed and modified at 55°C for 2h, filtered while hot, washed, and dried to obtain the organic acid modified biochar.

[0067] Table 4 Mass ratio of lauric acid, octadecylamine and secondary modified biochar

[0068]

[0069] The anti-seepage performance of the organic acid-modified biochar prepared in Examples 14 to 18 was tested, and the results of the anti-seepage performance test are shown in Table 5;

[0070] Table 5 Anti-seepage performance test results

[0071]

[0072] Embodiments 19 to 20

[0073] Organic acid modified biochar

[0074] 1) Under nitrogen protection, the biochar was preheated at 250°C for 20 min, and then calcined at 720°C for 10 min to obtain a primary modified biochar;

[0075] 2) According to the volume ratio of primary modified biochar to hydrochloric acid of 1 g: 20 mL, the primary modified biochar prepared in step 1) was placed in a solution with a concentration of 0.10 mol·L -1 The biochar was immersed in hydrochloric acid at 80°C for 30 min, washed and dried to obtain secondary modified biochar;

[0076] 3) According to the mass ratio of lauric acid, octadecylamine and secondary modified biochar recorded in Table 6, lauric acid, octadecylamine and the secondary modified biochar prepared in step 2) were mixed, heated to 55°C, and the lauric acid and octadecylamine were completely melted. The pH of the reaction system was adjusted to 5, and the mixture was immersed and modified at 55°C for 2h. The mixture was filtered while hot, washed, and dried to obtain the organic acid modified biochar.

[0077] Table 6 Mass ratio of lauric acid, octadecylamine and secondary modified biochar

[0078]

[0079] The anti-seepage performance of the organic acid-modified biochar prepared in Examples 19 to 20 was tested, and the results of the anti-seepage performance test are shown in Table 7;

[0080] Table 7 Anti-seepage performance test results

[0081]

[0082] It can be seen from the data in Tables 5 and 7 that changing the mass ratio of lauric acid, octadecylamine and secondary modified biochar will affect the anti-seepage properties of organic acid modified biochar to a certain extent. After testing, the optimal mass ratio of lauric acid, octadecylamine and secondary modified biochar is 9:4:1.

[0083] Examples 21-22

[0084] Organic acid modified biochar

[0085] 1) Under nitrogen protection, the biochar was preheated at 250°C for 20 min, and then calcined at 720°C for 10 min to obtain a primary modified biochar;

[0086] 2) According to the volume ratio of primary modified biochar to hydrochloric acid of 1 g: 20 mL, the primary modified biochar prepared in step 1) was placed in a solution with a concentration of 0.10 mol·L -1 The biochar was immersed in hydrochloric acid at 80°C for 30 min, washed and dried to obtain secondary modified biochar;

[0087] 3) According to the mass ratio of lauric acid, octadecylamine and secondary modified biochar of 9:4:1, lauric acid, octadecylamine and the secondary modified biochar prepared in step 2) are mixed, heated to 55°C, and after lauric acid and octadecylamine are completely melted, the pH of the reaction system is adjusted to 5, and the biochar is immersed and modified at 55°C for 2.5h or 3h, filtered while hot, washed, and dried to obtain the organic acid modified biochar.

[0088] The anti-seepage performance of the organic acid-modified biochar prepared in Examples 21 to 22 was tested, and the results of the anti-seepage performance test are shown in Table 8;

[0089] Table 8 Anti-seepage performance test results

[0090]

[0091] It can be seen from the data in Table 8 that changing the impregnation modification time during lauric acid and octadecylamine modification will affect the anti-seepage properties of organic acid modified biochar to a certain extent. Within the impregnation modification time range of 2 to 3 hours, with the increase of the impregnation modification time, the anti-seepage properties of organic acid modified biochar first gradually increased, and then gradually decreased, reaching the optimal anti-seepage properties at 2.5 hours, so 2.5 hours is the optimal impregnation modification time.

[0092] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the relevant field should understand that the specific implementation methods of the present invention can still be modified or replaced by equivalents. Any modification or equivalent replacement that does not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A method for preparing organic acid modified biochar, characterized in that: The following steps are involved: 1) calcining and modifying the biochar to obtain primary modified biochar; 2) placing the primary modified biochar prepared in step 1) in hydrochloric acid to perform impregnation modification on the primary modified biochar to obtain secondary modified biochar; 3) mixing lauric acid, octadecylamine and the secondary modified biochar prepared in step 2), heating, and impregnating and modifying the biochar to obtain the organic acid modified biochar.

2. The method for preparing organic acid-modified biochar according to claim 1, characterized in that: In step 1), the calcination modification is specifically as follows: under nitrogen gas protection, the biochar is preheated at 200-300° C. for 20 minutes, and then calcined and modified at 700-750° C. for 10 minutes.

3. The method for preparing organic acid-modified biochar according to claim 1, characterized in that: In step 2), the concentration of the hydrochloric acid is 0.05 to 0.20 mol·L -1 .

4. The method for preparing organic acid-modified biochar according to claim 1, characterized in that: In step 2), the volume ratio of the primary modified biochar to hydrochloric acid is 1 g: 20 mL.

5. The method for preparing organic acid-modified biochar according to claim 1, characterized in that: In step 2), the impregnation modification is specifically: impregnation modification at 70-90° C. for 30 minutes.

6. The method for preparing organic acid-modified biochar according to claim 1, characterized in that: In step 3), the mass ratio of lauric acid, octadecylamine and secondary modified biochar is (5-10):(3-5):

1.

7. The method for preparing organic acid-modified biochar according to claim 1, characterized in that: In step 3), the heating is specifically: heating to 55° C. to completely melt the lauric acid and octadecylamine.

8. The method for preparing organic acid-modified biochar according to claim 1, characterized in that: In step 3), the impregnation modification is specifically: impregnation modification at 55° C. for 2 to 3 hours.

9. An organic acid-modified biochar prepared by the method for preparing organic acid-modified biochar according to any one of claims 1 to 8.

10. Use of the organic acid-modified biochar prepared by the method for preparing the organic acid-modified biochar according to any one of claims 1 to 8 in anti-seepage of building engineering.

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